#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
/*
设置TCP接收缓冲区大小测试程序
*/
#define BUFFER_SIZE 1024
int main(int argc,char*argv[])
{
    if(argc <=2)
    {
        printf("usage: %s ip_address port_number recv_buffer_size\n",
        basename(argv[0]));
        return 1;
    }

    const char* ip = argv[1];
    int port = atoi(argv[2]);

   

    /*创建一个IPv4 socket地址*/
    struct sockaddr_in address;
    bzero(&address,sizeof(address));
    address.sin_family = AF_INET;
    inet_pton(AF_INET,ip,&address.sin_addr);
    address.sin_port= htons(port);

    int sock = socket(PF_INET,SOCK_STREAM,0);
    assert(sock>=0);

    int recvbuf = atoi(argv[3]);
    int len = sizeof(recvbuf);
    /*先设置TCP接收缓冲区的大小，然后立即读取之*/
    setsockopt(sock,SOL_SOCKET,SO_RCVBUF,&recvbuf,sizeof(recvbuf));
    getsockopt(sock,SOL_SOCKET,SO_RCVBUF,&recvbuf,(socklen_t*)&len);
    printf("the tcp reveive buffer size after setting is %d\n",recvbuf);


    int ret = bind(sock,(struct sockaddr*)&address,sizeof(address));
    assert(ret != -1);


    ret = listen(sock,5);
    assert(ret !=-1);



    struct sockaddr_in client;
    socklen_t client_addrlength = sizeof(client);
    int connfd = accept(sock,(struct sockaddr*)&client,&client_addrlength);
    if(connfd <0)
    {
        printf("errno is: %d\n",errno);
    }
    else{
        char buffer[BUFFER_SIZE];
        memset(buffer,'\0',BUFFER_SIZE);
        while(recv(connfd,buffer,BUFFER_SIZE-1,0)>0){}
        close(connfd);
    }
    close(sock);
    return 0;
}

